1. Field of the Invention
This invention relates to the area of machine tools and more particularly relates to a rotating spindle attachment device for detachably mounting an electrode on an electrical discharge machine (EDM). The invention includes a detachable spindle assembly incorporating an electric drive motor, threaded drive shaft, detachable electrode chuck, and water-tight seal(S) for use in mounting, rotating, and sealing a consumable electrode about its vertical axis relative to the workpiece.
2. Description of the Related Art
The present invention relates to a new and novel attachment device that can be detachably mounted for use with an electrical discharge machine (EDM). EDM machining is a relatively recent technological innovation and greatly expedites the forming of apertures, cavities or holes in a metal workpiece particularly where relatively small size apertures, cavities or holes are required and with relatively close tolerances.
In the present invention the electrode, being consumable, is detachably mounted on the EDM machine for rotational movement about its axis so as to remove metal from the workpiece, by fusion, so as to form apertures or holes in the workpiece as one would accomplish by conventional drilling or milling machines. Conventional EDM machines typically supply the means (via industrial standard fluid pumps and connectors) to communicate and deliver dielectric oil to the electrode and workpiece as it is desirable, during EDM machining, to effectively flush particles therefrom.
The ability to rotate the electrode makes the flushing operation easier because the rotational movement of the electrode mechanically aids in the exchange of dielectric fluid between the electrode and workpiece. In addition, a rotating electrode is engaged with the workpiece on all sides which causes the entire surface of the electrode to be used thus permitting a greater electrode surface area to be involved in the machining process which allows the machining current to be increased to improve the metal removal rate.
Also, electrode rotation greatly reduces side wall taper of the workpiece. Heretofore, known attachment devices for rotably mounting and sealing the electrode have not been entirely satisfactory especially from a cost effective point of view. In addition, such prior rotational mounting devices have not been satisfactory in enabling the operator to quickly and easily install the device to an EDM machine. Also, such prior rotational mounting devices have not been satisfactory in enabling the operator to quickly and easily replace and seal a plurality of electrode diameters while at the same time maintaining a high degree of machining efficiency and accuracy.